Crabmeat extraction method



1.970 w. L. LOCKERBY 3,548,

CRABMEAT EXTRACTION METHOD Filed Jail, 15. 1968 5 Sheets-Sheet 1 W. lee locks/5y lNVIfN'lU/Q.

ATTOIP/V'y Dec. 22, 1970 Filed Jan. 15, 1968 W. L. LOCKERBY CRABMEAT EXTRACTION METHOD 5 Sheet'sSheet 2 W. 1 es Z0c%er q INVIZN'IOR.

ATTORNEY W. L. LCCKERBY CRABMEAT EXTRACTION METHOD Dec. 22,1910

Fi led Jan- .15, 1968 5 Sheets-Sheet 3 W. A ee Zoe/46w INVILV'I'UR.

Afro/FIVE) Dec. 22, 1970 w. L. LOCKERBY GRABMEAT EXTRACTION METHOD 5 Sheets-Sheet 5 Filed Jan. 15, 1968 /III// W. L as lacks/fig INVEN'TOR.

ATTORNEY United States Patent M 3,548,449 CRABMEAT EXTRACTION METHOD W. Lee Lockerby, Houston, Tex., asslgnor to Avico, Inc., Houston, Tex., a corporation of Texas Filed Jan. 15, 1968, Ser. No. 697,966 Int. Cl. A22c 29/00 US. C]. 17-48 4 Claims ABSTRACT OF THE DISCLOSURE A machine and method for extracting meat from the body shells of crabs by the employment of centrifugal force, characterized by structures and procedures permitting operation at two different speeds operative to separately and successively extract the more valuable, relatively large lump meat sections in substantially unbroken condition; followed by extraction of the smaller, less valuable, flake meat sections.

- While numerous machines have been designed for extraction of the meat from the shells of crabs, some employing centrifugal force, none, to date so far as I am aware, have proven successful for a variety of reasons, including such problems as inability to effectively separate the meat cleanly from shell fragments, inefficiency in operation, complexity of the machines, inability to extract maximum amounts of the meat, and perhaps most importantly, the inability to remove the large lump sections in unbroken form. As these large lump sections constitute the meat portions which bring the highest price in the market, and, therefore, are the most valuable meat portions, failure to extract these sections in lump form greatly reduces the value of the extracted meat and thereby renders such earlier machines and methods generally uneconomic.

The present invention, therefore, has for its primary objects the provision of a machine and method of operation which overcome the diificulties in prior art devices, such as are enumerated above, and provides instead a relatively simple, compact machine for this purpose and a procedure which assures maximum extraction of the meat in forms calculated to have the highest market value.

In accordance with a preferred embodiment of this invention, the machine employs an arrangement which includes carrier trays, having means for securely holding crab body sections in positions to permit expulsion of the meat under centrifugal force. The trays are mounted for rotation by a variable speed electric motor having controls selectively enabling rotation of the carriers at different speeds for predetermined time intervals such as to cause expulsion from the crab body compartments first of the lump meat sections in unbroken form, followed by expulsion of the smaller flake meat sections. Automatically time means are also provided for separately collecting the two types of meat in sequence as produced.

Various other objects and advantages of this invention will become more readily apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates a preferred embodiment of this invention.

In the drawing:

FIG. 1 is an elevational view, in perspective, showing the complete machine;

FIG. 2 is a side elevational view showing the cover for the machine;

3,548,449 Patented Dec. 22, 1970 FIG. 3A is a vertical View, partly in elevation and partly in section, of the right-hand half of the machine viewed generally transversely of the machine;

FIG. 3B is a view similar to FIG. 3A showing the complementary left-hand half of the machine;

FIG. 4 is a plan view of one of the carrier trays;

FIG. 5 is a diagrammatic illustration of the several elements of the machine showing the electromechanical circuits and connections for operating and controlling the machine;

FIG. 6 is a detail in cross-section of a portion of one of the clamps for holding a crab body on a carrier tray;

FIG. 7 is a diagrammatic View showing the two-half portions of a crab as prepared for placing in the machine and illustrating the various partitions defining the meatenclosing compartments of the body shell, and

FIG. 8 is a cross-sectional view taken generally along line 8-8 of FIG. 7.

Referring to the drawing, the machine comprises a base, designated generally by the numeral 10, constructed of conventionally arranged vertical legs and cross-pieces including a top 11 having an opening 12. The opening is adapted to be closed by a dished cover 113 having an annular flange 13a about its open end and secured to a handle bar 14 having a rearward extension 15 pivotally mounted at 16 on one of the cross members of the frame, and carrying on its free-end a counterweight 17 designed to enable raising of the cover with a minimum of effort. The forward end of handle bar 14 forms a tongue 14a which is disposed to be releasably locked down in closed position over opening 12 by means of a pivoted latch 18 which includes a switch element 19 arranged to activate the electrical circuits for the machine, as will be subsequently described, when the handle is in the locked position and to open or deactivate the electrical circuits when the cover is raised, as seen in FIG. 2. Base 10 has mounted thereon a cabinet 10a which houses the various electrical and electromechanical elements employed in the operation of the machine, as will be described hereinafter.

Seated in opening :12, as best seen in FIGS. 3A and 3B, is an annular collector bowl, designated generally by the numeral 20, having a downwardly and outwardly sloping frusto-conical, peripheral wall 21, and a flat annular bottom 22 having a central opening 24 defined by an upwardly turned lip 23. The juncture of bottom 22 with peripheral wall 21 is defined by a smoothly carved portion 25. The upper end of wall 21 terminates in a radially outwardly extending flange 26 adapted to rest on the portion of top 11 defining opening 12, whereby to removably support bowl 20 in opening 12.

Disposed beneath bowl 20 is an electric motor 30 of the well known, generally conventional direct current, variable speed-type, having its power shaft 31 axially aligned with bowl opening 24. Power shaft 31 is coaxially connected by means of a coupling 32 to a main drive shaft 33 which extends upwardly through bowl opening 24 and terminates in a splined end 34 abuttable by a thrust bearing 35 mounted in the center of cover 13 when the latter is in its downward or closed position as best seen in FIGS. 3A and 3B.

A tubular housing 36 surrounds shafts 31 and 33 and has a flanged lower end 37 secured by means of cap screws 38 to the upper end of motor 30 and has a flanged upper end 39 secured by means of cap screws 40 to a horizontally disposed support plate 41 suitably mounted inside base 10 to function as a firm mounting for the main elements of the machine and provided. with a central opening 41a for accommodating the drive elements.

A tubular pillow block 42 is mounted in the bore of housing 36 surrounding power shaft 33 and carries an external flange 43 intermediate its ends by which it is supported on plate 41 about opening 41a and is secured to plate 41 by means of cap screws 44. The bore of pillow block 42 carries longitudinally spaced antifriction bearings 4545 in which drive shaft 33 is journalled.

A plurality of carrier trays, designated generally by the numeral (two shown), are disposed in vertically stacked relation about upper end 34 of main drive shaft 33. Each of the trays 50 comprises a flat horizontally disposed plate 51 having a central opening 52 adapted to slip over an adapter sleeve 53 having splined connection to shaft end 34 for rotation therewith. The lower end of sleeve 53 has an outwardly extending annular flange 54 which serves as a bottom rest for the lowermost one of trays 50, each of which carries a plurality of keys 55 extending radially inwardly of opening 52 for engagement in longitudinal spline grooves 56 in the exterior of adapter sleeve 53, whereby to lock the tray to the sleeve against relative rotation thereon, so that rotation of shaft 33 will be transmitted through adapter sleeve 53 to the several trays 50. The latter are each provided with a plurality of vertically disposed, circumferentially spacer bars 57 which determine the spacing between the trays and serve to support one tray above the other.

Each of trays 50 carries a plurality of radially extending, angularly spaced clips 58 pivoted at 59 on upstanding hinge lugs 60 and biased by means of spring 61 (FIGS. 4 and 6) to normally urge the forward end of the clip carrying downwardly and slightly inwardly turned gripping teeth 62 toward complementary upwardly projecting teeth 63 carried by the forward ends of clamp plates 64 mounted on plate 51. The spring biased clips and the cooperating teeth 62, 63 function to securely hold crab bodies (FIGS. 4 and 6) and restrain them against centrifugal force during rotation of the trays as will be described subsequently.

Mounted in bowl 20 between wall 21 and lip 23 be neath the lowermost tray 50, is a vertically disposed re tainer ring which is disposed for rotation about the axis of the bowl in close sliding relation to bottom 22 of the bowl. Ring 70 serves as an inner wall of the bowl to confine meat deposited in the bowl during operation of the machine, as will appear subsequently. Ring 70 is secured by means of a plurality of radial spokes or arms 71 to the upper end of a hub 72 which is rotatably mounted on an anti-friction bearing 72a about pillow block 42 above flange 43.

One of the arms 71 projects through ring 70 to provide an extension 74 which is rigidly secured to a vertically disposed wiper or scraper blade 75 extending radially between wall 21 and ring 70 and having a peripheral shape conforming closely to the shape of bowl 20 as defined by wall 21, bottom 22 and portion 25. As so formed, blade 75 will act to scrape the meat accumulating in bowl 20 between wall 21 and ring 70 around the interior of the bowl 20 toward a discharge duct 76 opening through bottom 22 of the bowl in response to rotation of arms 71 by hub 72, as will be described subsequently.

A horizontally disposed guard plate 77 is mounted to main shaft 33 just above the upper end of pillow block 42 and has its outer periphery formed to provide a downwardly torned lip 78 which terminates just above arms 71 and in alignment with lip 23 of bowl 20. Guard plate 77, which rotates with shaft 33, functions primarily to exclude meat particles or other detritus from falling into the parts of the machine below bowl 20 during operation of the machine.

Hub 72, with its connected elements, is driven independently of the drive for main shaft 33, and the drive elements for hub 72 include a sprocket 80 secured to hub 72 and driven by means of a chain belt 81 from a second sprocket 82 which is mounted on a shaft 83 driven through a gear box 84 by an electric motor 85, herein termed the wiper motor, the gear box and motor being suitably mounted beneath plate 41, with shaft 83 extending upwardly through an open 86 in plate 41, as best seen in FIG. 3B.

Mounted in base 10, generally beneath the lower end of discharge duct 76, is a horizontally disposed turntable 90 mounted for rotation on a shaft 91 extending upwardly from a gear box 92 drivingly connected to an electric motor 93, herein termed the indexing motor. Turntable 90 is adapted to support a pair of receptacles 94 and 95 which are alternatively rotated to positions beneath the discharge end of duct 76 to respectively receive the different types of crab meat extracted during operation of the machine, which will be described subsequently. The receptacles 94, 95 are held in place on turntable 90 by means of spring clips 96.

Operation of the machine will now be described, reference being had particularly to FIG. 5 which diagrammatically illustrates the electromechanical connections employed in the operation of the machine.

It will be understood that the crabs first will have been cooked in the conventional manner, after which the carapace is removed, as well as the stomach and its contents, leaving the cleaned body from which the claws, crawlers, and paddle elements will be removed at the knuckles. The body B (FIGS. 7 and 8) will then be cut in two along both sides of the center partition which will serve to remove the latter, thereby providing two half-body sections S, S, having the inner ends of the several body compartments containing the cooked crab meat open and exposed.

By reference to FIGS. 7 and 8, it will be seen that each half-body section S comprises upper and lower shells and 101, respectively, divided, generally transversely, by a plurality of thin shell partitions M to form a plurality of meat-containing compartments, the rearmost one of which is the body portion is designated by the number 102, and is substantially larger than the other compartments, each numbered 103. The meat, designated L, contained in compartment 102 constitutes that meat portion which is conventionally referred to as the lump meat, being a portion of substantially larger dimensions than the meat portions, designated F, in the compartments 103.

A half-body section S is positioned in each of the clamps 50 with the open ends of the compartments 102, 103 facing outwardly toward the periphery of the tray (FIG. 4). When the several trays (two in the illustrative embodiment) have been loaded with crab bodies, as described, the trays will be mounted over the upper end 34 of the drive shaft inside bowl 20, as illustrated in FIGS. 3A and 3B, and cover 13 will be closed and locked down by latch 18, closing safety switch 19. Thereupon, main switch will be closed by pressing starter button 111 (FIG. 1). This will close the circuit through a low speed timer 112 to main motor 30 through a speed controller 113 set to cause main shaft 33 to rotate at a first predetermined relatively low speed to develop relatively low centrifugal force but which will be suflicient only to expel the lump meat sections L from compartments 102 into bowl 20, but without disturbing the meat portions in compartments 103. The time interval required will be pre-set in the timer in relation to the selected speed to assure expulsion of meat sections L from compartments 102 of the body shells. The force at which the ejected meat sections will strike the inclined surface of wall 21 of the bowl will be sufficiently low at the speed employed to prevent shattering of the meat sections, so that unbroken meat sections L will fall to the bottom of the bowl.

In this first or lump meat removed stage of the operation the trays will be rotated to cause the tray peripheries to travel at a speed of about 4000 feet per minute for a time interval in the order of from about four to five seconds. This will usually be accomplished with a shaft speed of about 1800 r.p.m.

At the conclusion of the first time interval set in the low peed timer to expel the lump meat sections, the circuitry is arranged so that motor 30 will be stopped and a signal will be sent to a wiper timer 115 which will actuate wiper motor 85 to activate wiper blade 75, causing it to make a sweep about bowl so that the blade will push the lump meat sections collected in the bowl to a position over the upper end of discharge duct 76 through which the meat will fall into receptacle 94. As the wiper blade 75 completes its sweep around the bowl to position overlying duct 76, contact will be closed to a switch 116 and after a brief delay sufiicient to allow all the lump meat to fall through duct 76, will activate indexing motor 93 causing turn-table 90 to turn through an arc of 180, thereby moving container 94, containing the lump crab meat, out of alignment with duct 76 and rotating receptacle 95 into alignment with the lower end of duct 76. As the turn-table attains the end of the 180 rotation, a limit switch 117 will be closed, sending a signal to a high-speed timer 118 and a related speed-controller 119 to again activate motor and to cause it to drive shaft 33 and trays 50 at an increased speed suflicient to generate increased centrifugal force maintained for a time interval sufficient to cause expulsion of the smaller, more closely confined, meat particles or flakes from compartments 103 and discharge them into bowl 20.

In this second stage, higher speed operation for effecting extraction of the flake meat portions, the speed will be increased so as to produce a peripheral speed at the tray rim of about 7000 feet per minute, employing a drive shaft speed of about 3000 rpm. The time interval employed will again be about four to five seconds to complete the second stage extraction.

At the end of the timed second stage interval, a signal will be sent from the high speed timer 118 to wiper timer 115, to again activate wiper motor 85 to again drive wiper blade 75 around bowl 20 to scrape the accumulated flake meat to discharge duct 76 through which the meat will fall into receptacle 95 which had replaced receptacle 94 as previously described.

When the contact to switch 116 is again closed, indexing motor 93 will be again activated to rotate turn-table 90 to place a now-emptied receptacle 94 under duct 76. This action will close another limit switch 120 which will open main switch 110, cutting off the main current source and stopping all operations. Cover 13 may now be opened, so that trays 50 may be removed, and replaced by other trays loaded with fresh crab body sections, after which the cover is closed, main switch 110 again closed and the cycle of operations repeated.

It will be understood that the'rotational speeds and the time intervals employed for the successive meat extraction stages may be varied widely as may be desirable or necessary to attain the desired separate extraction and collection of the two different kinds of meat. The type of crab and the sizes will be factors to be considered in establishing the speeds and operating intervals.

It will be understood that the various electrical and electromechanical elements employed in the operation of the machine are all generally conventional and well known devices, and their details do not form a part of the present invention.

By means of the apparatus and method of operation heretofore described, it is possible not only to extract a maximum amount of the meat from the crab body shells but also to recover maximum amounts of the lump crabmeat sections in unbroken form. All the crabmeat will also be extracted cleanly and free of any shell particles so that even the lower valued flake meat will be marketable at highest prices. Also, removal of the crabmeat in the manner described eliminates manual handling, as is more commonly required, and thereby permits highly sanitary processing, and thus greatly reducing the danger of contamination.

It will be understood that various modifications and alterations may be made in the details of the apparatus and in the procedures heretofore described within the scope of the appended claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. The method of extracting the meat confined within the body shells of crabs, comprising,

(a) mounting the body shells on rotatable supports with open ends of the meat-confining compartments directed outwardly of the supports,

(b) rotating said supports for a first time interval and at a first speed selected to generate a centrifugal force sufficient only to expel without shattering the lump meat sections from the shells,

(c) thereafter rotating the supports for a second time interval and at a second higher speed selected to generate an increased centrifugal force sufficient to expel the relatively small flake meat sections from the shells, and

(d) separately collecting the meat sections expelled at the respective speeds.

2. The method according to claim 1 wherein said first speed is about 4000 feet per minute, said second speed is about 7000 feet per minute, and each of said time intervals is of the order of four to five seconds, said speeds being peripheral speeds of the meat-confining compartments.

3. The method for extracting meat from crabs, comprising,

(a) dividing a cooked crab body medially to provide two body sections having their respective meat-containing compartments open at the ends thereof adjacent the line of division,

(b) mounting the body sections on rotatable support means with said open ends directed outwardly of said support means,

(c) rotating said support means for a first time interval and at a first speed selected to generate centrifugal force sufficient only to expel without shattering the larger lump meat portions from their compartments,

(d) thereafter rotating the support means for a second time interval and at a second higher speed selected to generate increased centrifugal force sufiicient to expel the relatively small flake meat portions from their compartments, and

(e) separately collecting the meat portions expelled at the respective speeds.

4. The method according to claim 3 wherein said first speed is about 4000 feet per minute, said second speed is about 7000 feet per minute, and each of said time intervals is of the order of four to five seconds, said speeds being peripheral speeds of the meat-confining compartments.

References Cited UNITED STATES PATENTS 933,609 9/1909 Yancey 17-48 1,175,037 3/1916 Yancey 17-71 1,565,342 12/1925 Umrath 1771 2,104,027 1/1938 Dubus 1771 2,522,578 9/1950 Johnson 17-48 2,525,604 10/1950 Johnson 1771 LUCIE H. LAUDENSLAGER, Primary Examiner US. Cl. X.R. l771 

